There are two parameters, the cosmological constant Λ and the gravitational constant G, present in Einstein’s field equations. The Newtonian constant of gravitation G plays the role if a coupling constant between geometry and matter in the Einstein’s field equations. In an evolving Universe, it appears natural to look at this “constant” as a function of time. Numerous suggestions based on different arguments have been proposed in the past few decades in which G varies with time . Dirac  proposed a theory with variable G motivated by the occurrence of large numbers discovered by Weyl, Eddington and Dirac himself.